abstract:Clyclolobus is a smooth, essentially involute subdiscoidal goniatitid ammonoid that has sutures with a bifurcate ventral lobe, flared outwardly at the end, in which the halves may be secondarily trifurfate, ending in sharp, narrow projections. Lateral sutural elements follow an acuate line that swings first to the front, then sharply to the rear before becoming hidden by the next whorl.